I frequently want event tips that are out of the ordinary and out of the box. I find that Youtube is generally a good resource for this sort of ideas. All you need to do is browse through Youtube and do a search for "event suggestions" and you can find several hours worth of clips with a lot of good suggestions. The problem is, who has enough time to view them all? So I am on a continuous mission to compile some details to save me and also hopefully others some time.
Here is a great video with some insane party ideas - https://www.youtube.com/watch?v=wUlJSgYGmFw
Hope you see some good ideas for your future gathering on Youtube!